Compartmented operating systems have been available for several years in a form designed for handling and processing classified (military) information, using a containment mechanism enforced by a kernel of the operating system with mandatory access controls to resources of the computing platform such as files, processes and network connections. The operating system attaches labels to the resources and enforces a policy which governs the allowed interaction between these resources based on their label values. Most compartmented operating systems apply a policy based on the Bell-LaPadula model discussed in the paper “Applying Military Grade Security to the Internet” by C I Dalton and J F Griffin published in Computer Networks and ISDN Systems 29 (1997) 1799-1808.
Whilst a compartmented operating system is secure offering a relatively high degree of containment, it is desired to provide a method for demonstrating the integrity of a compartment. In particular, it is desired to demonstrate that a compartment is in a trusted state and will operate in a predicted manner. As one example, it is desired to confirm that the compartment is free from subversion, either arising inadvertently or through an unauthorised attack.